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A soluble factor from <em>Trypanosoma brucei rhodesiense</em> that prevents progression of activated human T lymphocytes through the cell cycle.
- Source :
- Immunology; Jun91, Vol. 73 Issue 2, p180-185, 6p
- Publication Year :
- 1991
-
Abstract
- African sleeping sickness is accompanied by a severe immunosuppression. As part of our efforts to examine the mechanisms by which this suppressive state is induced, we studied alterations in human T-lymphocyte function caused by Trypanosoma brucei rhodesiense. To this end, we used an in vitro system in which phytohaemagglutinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMC) were cultured in a medium containing soluble, non-dialysable parasite products. We were able to demonstrate significant suppression of both lympho-proliferation and interleukin-2 receptor (IL-2R) expression. These effects were found to be dose-dependent and reversible after 48 hr of culture. The suppressive effects of living trypanosomes and the soluble parasite products on lympho- proliferation and interleukin-2 receptor expression were similar in that both precluded the entry of PHA-activated PBMC into the cell cycle. Eighty to ninety-eight per cent of the activated cells remained arrested in the G0/Gla (early G1) phase even 48 hr after stimulation, i.e. when last tested. Parasite-induced expression could not be overcome by the addition of recombinant human 11-2. These results suggest that immunosuppression associated with African trypanosomiasis may result from parasite-induced alteration of very early events during lymphocyte activation, leading to a virtually complete block in cell cycle progression and inhibition of IL-2R expression. [ABSTRACT FROM AUTHOR]
- Subjects :
- T cells
LEUCOCYTES
LYMPHOCYTES
INTERLEUKIN-2
THERAPEUTICS
IMMUNOSUPPRESSION
Subjects
Details
- Language :
- English
- ISSN :
- 00192805
- Volume :
- 73
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Immunology
- Publication Type :
- Academic Journal
- Accession number :
- 13396019